A procedure for reproducible measurement of redox potential (E h) in dairy processes

Transcriptome analysis of Lactococcus lactis subsp. lactis during milk acidification as affected by dissolved oxygen and the redox potential

“…Parameters monitored during fermentation (DaqLogger FX112-4-2, Yokogawa, Japan) were dissolved oxygen concentration (Visiferm DO120, Hamilton Bonaduz, Switzerland), redox potential (E h7 ) and pH (Easyferm Plus Rx VP120, Hamilton Bonaduz, Switzerland). Calibration of the sensors and conversion of redox measurements into conventional redox potential at pH 7 (E h7 ) was performed as described before (Abraham et al, 2013;Tachon et al, 2010).…”

“…The starter cultures are exposed to various physicochemical stresses throughout cheese production, including acid, oxidative and osmotic stresses which affect their metabolic activity and, thereby, may influence the cheese quality (Bachmann et al, 2010;Raynaud et al, 2005). An important parameter affecting performance of starter cultures during milk fermentation is an oxidation-reduction (redox) potential (Abraham et al, 2013;Jeanson et al, 2009;McSweeney et al, 2010). The redox potential characterizes the ability of a system to accept (reduce) or donate (oxidize) electrons.…”

Implication of exofacial thiol groups in the reducing activity ofListeria monocytogenes

“…In order to obtain better stabilization of measured redox potential, the electrode was polished with aluminum powder before each experiment and treated with HCl- and pepsin-based Electrode Cleaning Solution (Grosseron, Nantes, France) for 30 min once per week. A control measure was performed in tap water before each experiment (Abraham et al, 2013). The measured redox values collected via the interface were converted to E h and E h7 values by using the software “Multi-bioreactors Central (3x E h , 3xpH, 3xT°C)” (Absciss, Fixin, France) using the equation E h = E m + E ref .…”

“…The E h measurement and monitoring are increasingly used as tools for the determination of bacterial activity in liquid media (Küsel and Dorsch, 2000), food products (Abraham et al, 2013; Alwazeer et al, 2003; Aubert et al, 2002), soils (Fiedler et al, 2007) and sediments (Schulz, 2000). Recent studies have emphasized that microbial cultures can generate a reducing activity during their growth depending on the redox potential of different cellular compartments, and their ability to grow in the presence of dioxygen.…”

Contribution of Lactococcus lactis Reducing Properties to the Downregulation of a Major Virulence Regulator in Staphylococcus aureus, the agr System

“…The redox probes were verified with a standard solution at ϩ300 mV Ϯ 30 mV. The measured redox potential (E m ) was corrected with regard to the reference hydrogen electrode to obtain E h , as previously described (E h ϭ E m ϩ E r , where E r ϭ 204 mV) (40,41). E h was not corrected with regard to pH, as the pH was maintained constant at 6.6 throughout fermentation.…”